This study compared the effects of strength/speed vs. repeated sprint training on repeated sprint ability in young elite soccer players. Elite male adolescents were assigned to either complex (strength/speed; N = 7) or repeated sprint (N = 7) training groups. During 10 weeks; complex training consisted of four to six series of 4-6 exercises (e.g., counter movement jumps, depth and plyometric jumps, agility drills, standing start and shuttle sprints), each repetition interspersed with at least 45 seconds of passive recovery. Repeated sprint training consisted of 2-3 sets of 5-6 x 15-20 m shuttle sprints (interspersed with 14 seconds of passive or 23 seconds of active recovery). The groups performed either complex or repeated sprint training once a week and maintained similar external training programs. Before and after training, performance was assessed by a counter movement jump, a hopping test, 10 and 30 m sprint times, and best and mean times on a repeated shuttle sprint ability test.

After training, except for the 10-m sprint, all performances significantly improved in both groups. Relative changes in the 30 m sprint were similar for both groups. Complex training tended to induce greater improvements in the counter movement jump and hop height when compared with repeated sprinting. In contrast, repeated sprint training induced greater improvement in repeated sprint ability and tended to enhance more the average repeated sprint times compared with complex training. [Usually, non-significant "trends" are not reported in this journal but in this case it is suspected that the power of the statistical analyses was insufficient and resulted in type II errors.]